1. The Mole and Molar Mass Chapter 4.2 Page 125 – 127

2. Mole The SI base unit that describes the amount of pure substance. Abbreviation = mol

3. How many is in a mole? 1 mol = 6.02 x 10 23 (Avogadro’s constant)

4. How many is 6.02 x 10 23 ? If you stack 6.02 x 10 23 sheets of paper, it will reach the sun! If you cover the United States with 6.02 x 10 23 popcorn kernels, it will cover the whole country 310 miles deep!

5. Molar Mass Mass in grams of 1 mole of a pure substance. The molar mass of an element is the same as the mass number in grams.

6. Example The mass number of magnesium is 24 amu, therefore the molar mass of magnesium is 24 grams. This means that one atom of magnesium weighs 24 amu and one mole of magnesium weighs 24 grams.

7. Practice: Find the molar mass 1.Argon, Ar = _______ 2.Zinc, Zn = _______ 3.Barium, Ba = _______ 4.Silver, Ag = ________

8. Practice: Find the molar mass 1.Argon, Ar = 40 g 2.Zinc, Zn = 65 g 3.Barium, Ba = 137 g 4.Silver, Ag = 108 g

9. Converting moles to mass Multiply the number of moles by the molar mass moles x molar mass = mass in grams

10. Converting moles to mass Determine the mass in grams of 5.50 mol of iron. 5.50 mol Fe x 56 g Fe = 308 g Fe 1 mol Fe

11. Answer to Practice Problems 1)80 g, S 2)72 g, Ca 3)6 g, C 4)205 g, Cu

12. Converting mass to moles Divide the mass by the molar mass mass / molar mass = number of moles

13. Converting mass to moles Determine the amount of iron in 352 grams of iron. 352 g Fe x 1 mol Fe = 6.3 mol Fe 56 g Fe

14. Answer to Practice Problems 1)5.1 mol C 2).62 mol Hg 3)1.4 mol Ti 4)7.1 mol N